All-optical hydrophone that is not sensitive to temperature or static pressure

摘要

The invention consists of: an optical hydrophone; and a fiber-optic element which forms a laser cavity and is housed inside a mechanical structure comprising an open rigid cylindrical body that defines a cavity containing a fluid, in which cavity the fiber-optic element is housed, said rigid body being sealed at the ends thereof by means of two stoppers that keep the fiber-optic element permanently under tension in a longitudinal rectilinear position inside the cavity. The stoppers are configured such as to: deform when the external pressure varies, thereby varying the length of the fiber-optic element; and deform when the temperature varies, thereby varying the length of the fiber-optic element and compensating for the variation experienced by the element as a result of the temperature variation. The mechanical structure also includes one or more openings that allow the static pressures to be balanced.